Chlorine dioxide is a chemical compound with the formula ClO2 that exists as yellowish-green gas above 11 °C (52 °F), a reddish-brown liquid between 11 and −59 °C, and as bright orange crystals below −59 °C (−74 °F). It is usually handled as an aqueous solution. It is commonly used as a bleach. Applications are in food processing and as a disinfectant.